It's an acidic byproduct of wine fermentation, and when you mix it with sodium bicarbonate and some water, you get carbon dioxide bubbles.
它是葡萄酒发酵的酸性副产品，当你将它与碳酸氢钠和一些水混合时， 会产生二氧化碳气泡。
Wine fermentation
原声例句
SciShow - Chemistry
中文百科
发酵 (葡萄酒) Fermentation in winemaking
（重定向自Wine fermentation）
发酵是葡萄酒酿制的一个重要过程，通过这一过程可以让葡萄汁转变为酒精饮料。这一过程中葡萄酒里的酵母和糖相互作用产生乙醇和二氧化碳。未发酵时葡萄汁中的氧气含量和温度等都是需要注意的事项，而且发酵过程中可能会有发酵停滞和数种葡萄酒变质现象发生。发酵葡萄酒的容器可以是不锈钢桶、敞开的木桶、橡木桶和葡萄酒瓶中。
英语百科
Fermentation in winemaking 发酵 (葡萄酒)
（重定向自Wine fermentation）
The process of fermentation in winemaking turns grape juice into an alcoholic beverage. During fermentation, yeasts transform sugars present in the juice into ethanol and carbon dioxide (as a by-product). In winemaking, the temperature and speed of fermentation are important considerations as well as the levels of oxygen present in the must at the start of the fermentation. The risk of stuck fermentation and the development of several wine faults can also occur during this stage, which can last anywhere from 5 to 14 days for primary fermentation and potentially another 5 to 10 days for a secondary fermentation. Fermentation may be done in stainless steel tanks, which is common with many white wines like Riesling, in an open wooden vat, inside a wine barrel and inside the wine bottle itself as in the production of many sparkling wines.